Sub-fin device isolation

Abstract

A fin-based structure may include fins on a surface of a semiconductor substrate. Each of the fins may include a doped portion proximate to the surface of the semiconductor substrate. The fin-based structure may also include an isolation layer disposed between the fins and on the surface of the semiconductor substrate. The fin-based structure may also include a recessed isolation liner on sidewalls of the doped portion of the fins. An unlined doped portion of the fins may extend from the recessed isolation liner to an active portion of the fins at a surface of the isolation layer. The isolation layer is disposed on the unlined doped portion of the fins.

What is claimed is: 
     
       1. A fin-based structure, comprising:
 a plurality of fins on a surface of a semiconductor substrate, each including a doped portion proximate to the surface of the semiconductor substrate; 
 an isolation layer disposed between the plurality of fins and on the surface of the semiconductor substrate; and 
 a recessed isolation liner on sidewalls of the doped portion of the plurality of fins, an unlined doped portion of the plurality of fins extending from the recessed isolation liner to a surface of the isolation layer, the isolation layer exposing an active portion of the plurality of fins and disposed on the unlined doped portion of the plurality of fins, in which a P-N junction is provided between the active portion and the doped portion of the plurality of fins. 
 
     
     
       2. The fin-based structure of  claim 1 , further comprising a separation layer disposed between the isolation layer and the recessed isolation liner. 
     
     
       3. The fin-based structure of  claim 2 , in which the separation layer is a nitride based dopant blocking layer. 
     
     
       4. The fin-based structure of  claim 1 , in which the recessed isolation liner further comprises a doped isolation liner on the sidewalls of the doped portion of the plurality of fins extending from the surface of the semiconductor substrate to the unlined doped portion of the plurality of fins. 
     
     
       5. The fin-based structure of  claim 1 , in which the isolation layer comprises a first layer disposed between the plurality of fins and a second layer at a base of the active portion of the plurality of fins and disposed on the unlined doped portion of the plurality of fins. 
     
     
       6. The fin-based structure of  claim 1  integrated into a mobile phone, a set top box, a music player, a video player, an entertainment unit, a navigation device, a computer, a hand-held personal communication systems (PCS) unit, a portable data unit, and/or a fixed location data unit. 
     
     
       7. A fin-based structure, comprising:
 a plurality of fins on a surface of a semiconductor substrate, each including a doped portion proximate to the surface of the semiconductor substrate; 
 a means for isolating disposed between the plurality of fins and on the surface of the semiconductor substrate; and 
 a recessed isolation liner on sidewalls of the doped portion of the plurality of fins, an unlined doped portion of the plurality of fins extending from the recessed isolation liner to a surface of the isolating means, the isolating means exposing an active portion of the plurality of fins and disposed on the unlined doped portion of the plurality of fins, in which a P-N junction is provided between the active portion and the doped portion of the plurality of fins. 
 
     
     
       8. The fin-based structure of  claim 7 , further comprising a separation layer disposed between the isolating means and the recessed isolation liner. 
     
     
       9. The fin-based structure of  claim 8 , in which the separation layer is a nitride based dopant blocking layer. 
     
     
       10. The fin-based structure of  claim 7 , in which the recessed isolation liner further comprises a doped isolation liner on the sidewalls of the doped portion of the plurality of fins extending from the surface of the semiconductor substrate to the unlined doped portion of the plurality of fins. 
     
     
       11. The fin-based structure of  claim 7 , in which the isolating means comprises a first layer disposed between the plurality of fins and a second layer at a base of the active portion of the plurality of fins and disposed on the unlined doped portion of the plurality of fins. 
     
     
       12. The fin-based structure of  claim 7  integrated into a mobile phone, a set top box, a music player, a video player, an entertainment unit, a navigation device, a computer, a hand-held personal communication systems (PCS) unit, a portable data unit, and/or a fixed location data unit.